text: /*
   *  ALSA sequencer Client Manager
   *  Copyright (c) 1998-2001 by Frank van de Pol <fvdpol@coil.demon.nl>
   *                             Jaroslav Kysela <perex@perex.cz>
   *                             Takashi Iwai <tiwai@suse.de>
   *
   *
   *   This program is free software; you can redistribute it and/or modify
   *   it under the terms of the GNU General Public License as published by
   *   the Free Software Foundation; either version 2 of the License, or
   *   (at your option) any later version.
   *
   *   This program is distributed in the hope that it will be useful,
   *   but WITHOUT ANY WARRANTY; without even the implied warranty of
   *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   *   GNU General Public License for more details.
   *
   *   You should have received a copy of the GNU General Public License
   *   along with this program; if not, write to the Free Software
   *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
   *
   */
  
  #include <linux/init.h>
  #include <linux/slab.h>
  #include <sound/core.h>
  #include <sound/minors.h>
  #include <linux/kmod.h>
  
  #include <sound/seq_kernel.h>
  #include "seq_clientmgr.h"
  #include "seq_memory.h"
  #include "seq_queue.h"
  #include "seq_timer.h"
  #include "seq_info.h"
  #include "seq_system.h"
  #include <sound/seq_device.h>
  #ifdef CONFIG_COMPAT
  #include <linux/compat.h>
  #endif
  
  /* Client Manager
  
   * this module handles the connections of userland and kernel clients
   *
   */
  
  /*
   * There are four ranges of client numbers (last two shared):
   * 0..15: global clients
   * 16..127: statically allocated client numbers for cards 0..27
   * 128..191: dynamically allocated client numbers for cards 28..31
   * 128..191: dynamically allocated client numbers for applications
   */
  
  /* number of kernel non-card clients */
  #define SNDRV_SEQ_GLOBAL_CLIENTS	16
  /* clients per cards, for static clients */
  #define SNDRV_SEQ_CLIENTS_PER_CARD	4
  /* dynamically allocated client numbers (both kernel drivers and user space) */
  #define SNDRV_SEQ_DYNAMIC_CLIENTS_BEGIN	128
  
  #define SNDRV_SEQ_LFLG_INPUT	0x0001
  #define SNDRV_SEQ_LFLG_OUTPUT	0x0002
  #define SNDRV_SEQ_LFLG_OPEN	(SNDRV_SEQ_LFLG_INPUT|SNDRV_SEQ_LFLG_OUTPUT)
  
  static DEFINE_SPINLOCK(clients_lock);
  static DEFINE_MUTEX(register_mutex);
  
  /*
   * client table
   */
  static char clienttablock[SNDRV_SEQ_MAX_CLIENTS];
  static struct snd_seq_client *clienttab[SNDRV_SEQ_MAX_CLIENTS];
  static struct snd_seq_usage client_usage;
  
  /*
   * prototypes
   */
  static int bounce_error_event(struct snd_seq_client *client,
  			      struct snd_seq_event *event,
  			      int err, int atomic, int hop);
  static int snd_seq_deliver_single_event(struct snd_seq_client *client,
  					struct snd_seq_event *event,
  					int filter, int atomic, int hop);
  
  /*
   */
  
  static inline mm_segment_t snd_enter_user(void)
  {
  	mm_segment_t fs = get_fs();
  	set_fs(get_ds());
  	return fs;
  }
  
  static inline void snd_leave_user(mm_segment_t fs)
  {
  	set_fs(fs);
  }
  
  /*
   */
  static inline unsigned short snd_seq_file_flags(struct file *file)
  {
          switch (file->f_mode & (FMODE_READ | FMODE_WRITE)) {
          case FMODE_WRITE:
                  return SNDRV_SEQ_LFLG_OUTPUT;
          case FMODE_READ:
                  return SNDRV_SEQ_LFLG_INPUT;
          default:
                  return SNDRV_SEQ_LFLG_OPEN;
          }
  }
  
  static inline int snd_seq_write_pool_allocated(struct snd_seq_client *client)
  {
  	return snd_seq_total_cells(client->pool) > 0;
  }
  
  /* return pointer to client structure for specified id */
  static struct snd_seq_client *clientptr(int clientid)
  {
  	if (clientid < 0 || clientid >= SNDRV_SEQ_MAX_CLIENTS) {
  		snd_printd("Seq: oops. Trying to get pointer to client %d\n",
  			   clientid);
  		return NULL;
  	}
  	return clienttab[clientid];
  }
  
  struct snd_seq_client *snd_seq_client_use_ptr(int clientid)
  {
  	unsigned long flags;
  	struct snd_seq_client *client;
  
  	if (clientid < 0 || clientid >= SNDRV_SEQ_MAX_CLIENTS) {
  		snd_printd("Seq: oops. Trying to get pointer to client %d\n",
  			   clientid);
  		return NULL;
  	}
  	spin_lock_irqsave(&clients_lock, flags);
  	client = clientptr(clientid);
  	if (client)
  		goto __lock;
  	if (clienttablock[clientid]) {
  		spin_unlock_irqrestore(&clients_lock, flags);
  		return NULL;
  	}
  	spin_unlock_irqrestore(&clients_lock, flags);
  #ifdef CONFIG_MODULES
  	if (!in_interrupt()) {
  		static char client_requested[SNDRV_SEQ_GLOBAL_CLIENTS];
  		static char card_requested[SNDRV_CARDS];
  		if (clientid < SNDRV_SEQ_GLOBAL_CLIENTS) {
  			int idx;
  
  			if (!client_requested[clientid]) {
  				client_requested[clientid] = 1;
  				for (idx = 0; idx < 15; idx++) {
  					if (seq_client_load[idx] < 0)
  						break;
  					if (seq_client_load[idx] == clientid) {
  						request_module("snd-seq-client-%i",
  							       clientid);
  						break;
  					}
  				}
  			}
  		} else if (clientid < SNDRV_SEQ_DYNAMIC_CLIENTS_BEGIN) {
  			int card = (clientid - SNDRV_SEQ_GLOBAL_CLIENTS) /
  				SNDRV_SEQ_CLIENTS_PER_CARD;
  			if (card < snd_ecards_limit) {
  				if (! card_requested[card]) {
  					card_requested[card] = 1;
  					snd_request_card(card);
  				}
  				snd_seq_device_load_drivers();
  			}
  		}
  		spin_lock_irqsave(&clients_lock, flags);
  		client = clientptr(clientid);
  		if (client)
  			goto __lock;
  		spin_unlock_irqrestore(&clients_lock, flags);
  	}
  #endif
  	return NULL;
  
        __lock:
  	snd_use_lock_use(&client->use_lock);
  	spin_unlock_irqrestore(&clients_lock, flags);
  	return client;
  }
  
  static void usage_alloc(struct snd_seq_usage *res, int num)
  {
  	res->cur += num;
  	if (res->cur > res->peak)
  		res->peak = res->cur;
  }
  
  static void usage_free(struct snd_seq_usage *res, int num)
  {
  	res->cur -= num;
  }
  
  /* initialise data structures */
  int __init client_init_data(void)
  {
  	/* zap out the client table */
  	memset(&clienttablock, 0, sizeof(clienttablock));
  	memset(&clienttab, 0, sizeof(clienttab));
  	return 0;
  }
  
  static struct snd_seq_client *seq_create_client1(int client_index, int poolsize)
  {
  	unsigned long flags;
  	int c;
  	struct snd_seq_client *client;
  
  	/* init client data */
  	client = kzalloc(sizeof(*client), GFP_KERNEL);
  	if (client == NULL)
  		return NULL;
  	client->pool = snd_seq_pool_new(poolsize);
  	if (client->pool == NULL) {
  		kfree(client);
  		return NULL;
  	}
  	client->type = NO_CLIENT;
  	snd_use_lock_init(&client->use_lock);
  	rwlock_init(&client->ports_lock);
  	mutex_init(&client->ports_mutex);
  	INIT_LIST_HEAD(&client->ports_list_head);
  
  	/* find free slot in the client table */
  	spin_lock_irqsave(&clients_lock, flags);
  	if (client_index < 0) {
  		for (c = SNDRV_SEQ_DYNAMIC_CLIENTS_BEGIN;
  		     c < SNDRV_SEQ_MAX_CLIENTS;
  		     c++) {
  			if (clienttab[c] || clienttablock[c])
  				continue;
  			clienttab[client->number = c] = client;
  			spin_unlock_irqrestore(&clients_lock, flags);
  			return client;
  		}
  	} else {
  		if (clienttab[client_index] == NULL && !clienttablock[client_index]) {
  			clienttab[client->number = client_index] = client;
  			spin_unlock_irqrestore(&clients_lock, flags);
  			return client;
  		}
  	}
  	spin_unlock_irqrestore(&clients_lock, flags);
  	snd_seq_pool_delete(&client->pool);
  	kfree(client);
  	return NULL;	/* no free slot found or busy, return failure code */
  }
  
  static int seq_free_client1(struct snd_seq_client *client)
  {
  	unsigned long flags;
  
  	if (!client)
  		return 0;
  	snd_seq_delete_all_ports(client);
  	snd_seq_queue_client_leave(client->number);
  	spin_lock_irqsave(&clients_lock, flags);
  	clienttablock[client->number] = 1;
  	clienttab[client->number] = NULL;
  	spin_unlock_irqrestore(&clients_lock, flags);
  	snd_use_lock_sync(&client->use_lock);
  	snd_seq_queue_client_termination(client->number);
  	if (client->pool)
  		snd_seq_pool_delete(&client->pool);
  	spin_lock_irqsave(&clients_lock, flags);
  	clienttablock[client->number] = 0;
  	spin_unlock_irqrestore(&clients_lock, flags);
  	return 0;
  }
  
  static void seq_free_client(struct snd_seq_client * client)
  {
  	mutex_lock(&register_mutex);
  	switch (client->type) {
  	case NO_CLIENT:
  		snd_printk(KERN_WARNING "Seq: Trying to free unused client %d\n",
  			   client->number);
  		break;
  	case USER_CLIENT:
  	case KERNEL_CLIENT:
  		seq_free_client1(client);
  		usage_free(&client_usage, 1);
  		break;
  
  	default:
  		snd_printk(KERN_ERR "Seq: Trying to free client %d with undefined type = %d\n",
  			   client->number, client->type);
  	}
  	mutex_unlock(&register_mutex);
  
  	snd_seq_system_client_ev_client_exit(client->number);
  }
  
  /* -------------------------------------------------------- */
  
  /* create a user client */
  static int snd_seq_open(struct inode *inode, struct file *file)
  {
  	int c, mode;			/* client id */
  	struct snd_seq_client *client;
  	struct snd_seq_user_client *user;
  	int err;
  
  	err = nonseekable_open(inode, file);
  	if (err < 0)
  		return err;
  
  	if (mutex_lock_interruptible(&register_mutex))
  		return -ERESTARTSYS;
  	client = seq_create_client1(-1, SNDRV_SEQ_DEFAULT_EVENTS);
  	if (client == NULL) {
  		mutex_unlock(&register_mutex);
  		return -ENOMEM;	/* failure code */
  	}
  
  	mode = snd_seq_file_flags(file);
  	if (mode & SNDRV_SEQ_LFLG_INPUT)
  		client->accept_input = 1;
  	if (mode & SNDRV_SEQ_LFLG_OUTPUT)
  		client->accept_output = 1;
  
  	user = &client->data.user;
  	user->fifo = NULL;
  	user->fifo_pool_size = 0;
  
  	if (mode & SNDRV_SEQ_LFLG_INPUT) {
  		user->fifo_pool_size = SNDRV_SEQ_DEFAULT_CLIENT_EVENTS;
  		user->fifo = snd_seq_fifo_new(user->fifo_pool_size);
  		if (user->fifo == NULL) {
  			seq_free_client1(client);
  			kfree(client);
  			mutex_unlock(&register_mutex);
  			return -ENOMEM;
  		}
  	}
  
  	usage_alloc(&client_usage, 1);
  	client->type = USER_CLIENT;
  	mutex_unlock(&register_mutex);
  
  	c = client->number;
  	file->private_data = client;
  
  	/* fill client data */
  	user->file = file;
  	sprintf(client->name, "Client-%d", c);
  
  	/* make others aware this new client */
  	snd_seq_system_client_ev_client_start(c);
  
  	return 0;
  }
  
  /* delete a user client */
  static int snd_seq_release(struct inode *inode, struct file *file)
  {
  	struct snd_seq_client *client = file->private_data;
  
  	if (client) {
  		seq_free_client(client);
  		if (client->data.user.fifo)
  			snd_seq_fifo_delete(&client->data.user.fifo);
  		kfree(client);
  	}
  
  	return 0;
  }
  
  /* handle client read() */
  /* possible error values:
   *	-ENXIO	invalid client or file open mode
   *	-ENOSPC	FIFO overflow (the flag is cleared after this error report)
   *	-EINVAL	no enough user-space buffer to write the whole event
   *	-EFAULT	seg. fault during copy to user space
   */
  static ssize_t snd_seq_read(struct file *file, char __user *buf, size_t count,
  			    loff_t *offset)
  {
  	struct snd_seq_client *client = file->private_data;
  	struct snd_seq_fifo *fifo;
  	int err;
  	long result = 0;
  	struct snd_seq_event_cell *cell;
  
  	if (!(snd_seq_file_flags(file) & SNDRV_SEQ_LFLG_INPUT))
  		return -ENXIO;
  
  	if (!access_ok(VERIFY_WRITE, buf, count))
  		return -EFAULT;
  
  	/* check client structures are in place */
  	if (snd_BUG_ON(!client))
  		return -ENXIO;
  
  	if (!client->accept_input || (fifo = client->data.user.fifo) == NULL)
  		return -ENXIO;
  
  	if (atomic_read(&fifo->overflow) > 0) {
  		/* buffer overflow is detected */
  		snd_seq_fifo_clear(fifo);
  		/* return error code */
  		return -ENOSPC;
  	}
  
  	cell = NULL;
  	err = 0;
  	snd_seq_fifo_lock(fifo);
  
  	/* while data available in queue */
  	while (count >= sizeof(struct snd_seq_event)) {
  		int nonblock;
  
  		nonblock = (file->f_flags & O_NONBLOCK) || result > 0;
  		if ((err = snd_seq_fifo_cell_out(fifo, &cell, nonblock)) < 0) {
  			break;
  		}
  		if (snd_seq_ev_is_variable(&cell->event)) {
  			struct snd_seq_event tmpev;
  			tmpev = cell->event;
  			tmpev.data.ext.len &= ~SNDRV_SEQ_EXT_MASK;
  			if (copy_to_user(buf, &tmpev, sizeof(struct snd_seq_event))) {
  				err = -EFAULT;
  				break;
  			}
  			count -= sizeof(struct snd_seq_event);
  			buf += sizeof(struct snd_seq_event);
  			err = snd_seq_expand_var_event(&cell->event, count,
  						       (char __force *)buf, 0,
  						       sizeof(struct snd_seq_event));
  			if (err < 0)
  				break;
  			result += err;
  			count -= err;
  			buf += err;
  		} else {
  			if (copy_to_user(buf, &cell->event, sizeof(struct snd_seq_event))) {
  				err = -EFAULT;
  				break;
  			}
  			count -= sizeof(struct snd_seq_event);
  			buf += sizeof(struct snd_seq_event);
  		}
  		snd_seq_cell_free(cell);
  		cell = NULL; /* to be sure */
  		result += sizeof(struct snd_seq_event);
  	}
  
  	if (err < 0) {
  		if (cell)
  			snd_seq_fifo_cell_putback(fifo, cell);
  		if (err == -EAGAIN && result > 0)
  			err = 0;
  	}
  	snd_seq_fifo_unlock(fifo);
  
  	return (err < 0) ? err : result;
  }
  
  /*
   * check access permission to the port
   */
  static int check_port_perm(struct snd_seq_client_port *port, unsigned int flags)
  {
  	if ((port->capability & flags) != flags)
  		return 0;
  	return flags;
  }
  
  /*
   * check if the destination client is available, and return the pointer
   * if filter is non-zero, client filter bitmap is tested.
   */
  static struct snd_seq_client *get_event_dest_client(struct snd_seq_event *event,
  						    int filter)
  {
  	struct snd_seq_client *dest;
  
  	dest = snd_seq_client_use_ptr(event->dest.client);
  	if (dest == NULL)
  		return NULL;
  	if (! dest->accept_input)
  		goto __not_avail;
  	if ((dest->filter & SNDRV_SEQ_FILTER_USE_EVENT) &&
  	    ! test_bit(event->type, dest->event_filter))
  		goto __not_avail;
  	if (filter && !(dest->filter & filter))
  		goto __not_avail;
  
  	return dest; /* ok - accessible */
  __not_avail:
  	snd_seq_client_unlock(dest);
  	return NULL;
  }
  
  /*
   * Return the error event.
   *
   * If the receiver client is a user client, the original event is
   * encapsulated in SNDRV_SEQ_EVENT_BOUNCE as variable length event.  If
   * the original event is also variable length, the external data is
   * copied after the event record.
   * If the receiver client is a kernel client, the original event is
   * quoted in SNDRV_SEQ_EVENT_KERNEL_ERROR, since this requires no extra
   * kmalloc.
   */
  static int bounce_error_event(struct snd_seq_client *client,
  			      struct snd_seq_event *event,
  			      int err, int atomic, int hop)
  {
  	struct snd_seq_event bounce_ev;
  	int result;
  
  	if (client == NULL ||
  	    ! (client->filter & SNDRV_SEQ_FILTER_BOUNCE) ||
  	    ! client->accept_input)
  		return 0; /* ignored */
  
  	/* set up quoted error */
  	memset(&bounce_ev, 0, sizeof(bounce_ev));
  	bounce_ev.type = SNDRV_SEQ_EVENT_KERNEL_ERROR;
  	bounce_ev.flags = SNDRV_SEQ_EVENT_LENGTH_FIXED;
  	bounce_ev.queue = SNDRV_SEQ_QUEUE_DIRECT;
  	bounce_ev.source.client = SNDRV_SEQ_CLIENT_SYSTEM;
  	bounce_ev.source.port = SNDRV_SEQ_PORT_SYSTEM_ANNOUNCE;
  	bounce_ev.dest.client = client->number;
  	bounce_ev.dest.port = event->source.port;
  	bounce_ev.data.quote.origin = event->dest;
  	bounce_ev.data.quote.event = event;
  	bounce_ev.data.quote.value = -err; /* use positive value */
  	result = snd_seq_deliver_single_event(NULL, &bounce_ev, 0, atomic, hop + 1);
  	if (result < 0) {
  		client->event_lost++;
  		return result;
  	}
  
  	return result;
  }
  
  /*
   * rewrite the time-stamp of the event record with the curren time
   * of the given queue.
   * return non-zero if updated.
   */
  static int update_timestamp_of_queue(struct snd_seq_event *event,
  				     int queue, int real_time)
  {
  	struct snd_seq_queue *q;
  
  	q = queueptr(queue);
  	if (! q)
  		return 0;
  	event->queue = queue;
  	event->flags &= ~SNDRV_SEQ_TIME_STAMP_MASK;
  	if (real_time) {
  		event->time.time = snd_seq_timer_get_cur_time(q->timer);
  		event->flags |= SNDRV_SEQ_TIME_STAMP_REAL;
  	} else {
  		event->time.tick = snd_seq_timer_get_cur_tick(q->timer);
  		event->flags |= SNDRV_SEQ_TIME_STAMP_TICK;
  	}
  	queuefree(q);
  	return 1;
  }
  
  /*
   * deliver an event to the specified destination.
   * if filter is non-zero, client filter bitmap is tested.
   *
   *  RETURN VALUE: 0 : if succeeded
   *		 <0 : error
   */
  static int snd_seq_deliver_single_event(struct snd_seq_client *client,
  					struct snd_seq_event *event,
  					int filter, int atomic, int hop)
  {
  	struct snd_seq_client *dest = NULL;
  	struct snd_seq_client_port *dest_port = NULL;
  	int result = -ENOENT;
  	int direct;
  
  	direct = snd_seq_ev_is_direct(event);
  
  	dest = get_event_dest_client(event, filter);
  	if (dest == NULL)
  		goto __skip;
  	dest_port = snd_seq_port_use_ptr(dest, event->dest.port);
  	if (dest_port == NULL)
  		goto __skip;
  
  	/* check permission */
  	if (! check_port_perm(dest_port, SNDRV_SEQ_PORT_CAP_WRITE)) {
  		result = -EPERM;
  		goto __skip;
  	}
  
  	if (dest_port->timestamping)
  		update_timestamp_of_queue(event, dest_port->time_queue,
  					  dest_port->time_real);
  
  	switch (dest->type) {
  	case USER_CLIENT:
  		if (dest->data.user.fifo)
  			result = snd_seq_fifo_event_in(dest->data.user.fifo, event);
  		break;
  
  	case KERNEL_CLIENT:
  		if (dest_port->event_input == NULL)
  			break;
  		result = dest_port->event_input(event, direct,
  						dest_port->private_data,
  						atomic, hop);
  		break;
  	default:
  		break;
  	}
  
    __skip:
  	if (dest_port)
  		snd_seq_port_unlock(dest_port);
  	if (dest)
  		snd_seq_client_unlock(dest);
  
  	if (result < 0 && !direct) {
  		result = bounce_error_event(client, event, result, atomic, hop);
  	}
  	return result;
  }
  
  /*
   * send the event to all subscribers:
   */
  static int deliver_to_subscribers(struct snd_seq_client *client,
  				  struct snd_seq_event *event,
  				  int atomic, int hop)
  {
  	struct snd_seq_subscribers *subs;
  	int err = 0, num_ev = 0;
  	struct snd_seq_event event_saved;
  	struct snd_seq_client_port *src_port;
  	struct snd_seq_port_subs_info *grp;
  
  	src_port = snd_seq_port_use_ptr(client, event->source.port);
  	if (src_port == NULL)
  		return -EINVAL; /* invalid source port */
  	/* save original event record */
  	event_saved = *event;
  	grp = &src_port->c_src;
  
  	/* lock list */
  	if (atomic)
  		read_lock(&grp->list_lock);
  	else
  		down_read(&grp->list_mutex);
  	list_for_each_entry(subs, &grp->list_head, src_list) {
  		event->dest = subs->info.dest;
  		if (subs->info.flags & SNDRV_SEQ_PORT_SUBS_TIMESTAMP)
  			/* convert time according to flag with subscription */
  			update_timestamp_of_queue(event, subs->info.queue,
  						  subs->info.flags & SNDRV_SEQ_PORT_SUBS_TIME_REAL);
  		err = snd_seq_deliver_single_event(client, event,
  						   0, atomic, hop);
  		if (err < 0)
  			break;
  		num_ev++;
  		/* restore original event record */
  		*event = event_saved;
  	}
  	if (atomic)
  		read_unlock(&grp->list_lock);
  	else
  		up_read(&grp->list_mutex);
  	*event = event_saved; /* restore */
  	snd_seq_port_unlock(src_port);
  	return (err < 0) ? err : num_ev;
  }
  
  #ifdef SUPPORT_BROADCAST
  /*
   * broadcast to all ports:
   */
  static int port_broadcast_event(struct snd_seq_client *client,
  				struct snd_seq_event *event,
  				int atomic, int hop)
  {
  	int num_ev = 0, err = 0;
  	struct snd_seq_client *dest_client;
  	struct snd_seq_client_port *port;
  
  	dest_client = get_event_dest_client(event, SNDRV_SEQ_FILTER_BROADCAST);
  	if (dest_client == NULL)
  		return 0; /* no matching destination */
  
  	read_lock(&dest_client->ports_lock);
  	list_for_each_entry(port, &dest_client->ports_list_head, list) {
  		event->dest.port = port->addr.port;
  		/* pass NULL as source client to avoid error bounce */
  		err = snd_seq_deliver_single_event(NULL, event,
  						   SNDRV_SEQ_FILTER_BROADCAST,
  						   atomic, hop);
  		if (err < 0)
  			break;
  		num_ev++;
  	}
  	read_unlock(&dest_client->ports_lock);
  	snd_seq_client_unlock(dest_client);
  	event->dest.port = SNDRV_SEQ_ADDRESS_BROADCAST; /* restore */
  	return (err < 0) ? err : num_ev;
  }
  
  /*
   * send the event to all clients:
   * if destination port is also ADDRESS_BROADCAST, deliver to all ports.
   */
  static int broadcast_event(struct snd_seq_client *client,
  			   struct snd_seq_event *event, int atomic, int hop)
  {
  	int err = 0, num_ev = 0;
  	int dest;
  	struct snd_seq_addr addr;
  
  	addr = event->dest; /* save */
  
  	for (dest = 0; dest < SNDRV_SEQ_MAX_CLIENTS; dest++) {
  		/* don't send to itself */
  		if (dest == client->number)
  			continue;
  		event->dest.client = dest;
  		event->dest.port = addr.port;
  		if (addr.port == SNDRV_SEQ_ADDRESS_BROADCAST)
  			err = port_broadcast_event(client, event, atomic, hop);
  		else
  			/* pass NULL as source client to avoid error bounce */
  			err = snd_seq_deliver_single_event(NULL, event,
  							   SNDRV_SEQ_FILTER_BROADCAST,
  							   atomic, hop);
  		if (err < 0)
  			break;
  		num_ev += err;
  	}
  	event->dest = addr; /* restore */
  	return (err < 0) ? err : num_ev;
  }
  
  /* multicast - not supported yet */
  static int multicast_event(struct snd_seq_client *client, struct snd_seq_event *event,
  			   int atomic, int hop)
  {
  	snd_printd("seq: multicast not supported yet.\n");
  	return 0; /* ignored */
  }
  #endif /* SUPPORT_BROADCAST */
  
  /* deliver an event to the destination port(s).
   * if the event is to subscribers or broadcast, the event is dispatched
   * to multiple targets.
   *
   * RETURN VALUE: n > 0  : the number of delivered events.
   *               n == 0 : the event was not passed to any client.
   *               n < 0  : error - event was not processed.
   */
  static int snd_seq_deliver_event(struct snd_seq_client *client, struct snd_seq_event *event,
  				 int atomic, int hop)
  {
  	int result;
  
  	hop++;
  	if (hop >= SNDRV_SEQ_MAX_HOPS) {
  		snd_printd("too long delivery path (%d:%d->%d:%d)\n",
  			   event->source.client, event->source.port,
  			   event->dest.client, event->dest.port);
  		return -EMLINK;
  	}
  
  	if (event->queue == SNDRV_SEQ_ADDRESS_SUBSCRIBERS ||
  	    event->dest.client == SNDRV_SEQ_ADDRESS_SUBSCRIBERS)
  		result = deliver_to_subscribers(client, event, atomic, hop);
  #ifdef SUPPORT_BROADCAST
  	else if (event->queue == SNDRV_SEQ_ADDRESS_BROADCAST ||
  		 event->dest.client == SNDRV_SEQ_ADDRESS_BROADCAST)
  		result = broadcast_event(client, event, atomic, hop);
  	else if (event->dest.client >= SNDRV_SEQ_MAX_CLIENTS)
  		result = multicast_event(client, event, atomic, hop);
  	else if (event->dest.port == SNDRV_SEQ_ADDRESS_BROADCAST)
  		result = port_broadcast_event(client, event, atomic, hop);
  #endif
  	else
  		result = snd_seq_deliver_single_event(client, event, 0, atomic, hop);
  
  	return result;
  }
  
  /*
   * dispatch an event cell:
   * This function is called only from queue check routines in timer
   * interrupts or after enqueued.
   * The event cell shall be released or re-queued in this function.
   *
   * RETURN VALUE: n > 0  : the number of delivered events.
   *		 n == 0 : the event was not passed to any client.
   *		 n < 0  : error - event was not processed.
   */
  int snd_seq_dispatch_event(struct snd_seq_event_cell *cell, int atomic, int hop)
  {
  	struct snd_seq_client *client;
  	int result;
  
  	if (snd_BUG_ON(!cell))
  		return -EINVAL;
  
  	client = snd_seq_client_use_ptr(cell->event.source.client);
  	if (client == NULL) {
  		snd_seq_cell_free(cell); /* release this cell */
  		return -EINVAL;
  	}
  
  	if (cell->event.type == SNDRV_SEQ_EVENT_NOTE) {
  		/* NOTE event:
  		 * the event cell is re-used as a NOTE-OFF event and
  		 * enqueued again.
  		 */
  		struct snd_seq_event tmpev, *ev;
  
  		/* reserve this event to enqueue note-off later */
  		tmpev = cell->event;
  		tmpev.type = SNDRV_SEQ_EVENT_NOTEON;
  		result = snd_seq_deliver_event(client, &tmpev, atomic, hop);
  
  		/*
  		 * This was originally a note event.  We now re-use the
  		 * cell for the note-off event.
  		 */
  
  		ev = &cell->event;
  		ev->type = SNDRV_SEQ_EVENT_NOTEOFF;
  		ev->flags |= SNDRV_SEQ_PRIORITY_HIGH;
  
  		/* add the duration time */
  		switch (ev->flags & SNDRV_SEQ_TIME_STAMP_MASK) {
  		case SNDRV_SEQ_TIME_STAMP_TICK:
  			ev->time.tick += ev->data.note.duration;
  			break;
  		case SNDRV_SEQ_TIME_STAMP_REAL:
  			/* unit for duration is ms */
  			ev->time.time.tv_nsec += 1000000 * (ev->data.note.duration % 1000);
  			ev->time.time.tv_sec += ev->data.note.duration / 1000 +
  						ev->time.time.tv_nsec / 1000000000;
  			ev->time.time.tv_nsec %= 1000000000;
  			break;
  		}
  		ev->data.note.velocity = ev->data.note.off_velocity;
  
  		/* Now queue this cell as the note off event */
  		if (snd_seq_enqueue_event(cell, atomic, hop) < 0)
  			snd_seq_cell_free(cell); /* release this cell */
  
  	} else {
  		/* Normal events:
  		 * event cell is freed after processing the event
  		 */
  
  		result = snd_seq_deliver_event(client, &cell->event, atomic, hop);
  		snd_seq_cell_free(cell);
  	}
  
  	snd_seq_client_unlock(client);
  	return result;
  }
  
  /* Allocate a cell from client pool and enqueue it to queue:
   * if pool is empty and blocking is TRUE, sleep until a new cell is
   * available.
   */
  static int snd_seq_client_enqueue_event(struct snd_seq_client *client,
  					struct snd_seq_event *event,
  					struct file *file, int blocking,
  					int atomic, int hop)
  {
  	struct snd_seq_event_cell *cell;
  	int err;
  
  	/* special queue values - force direct passing */
  	if (event->queue == SNDRV_SEQ_ADDRESS_SUBSCRIBERS) {
  		event->dest.client = SNDRV_SEQ_ADDRESS_SUBSCRIBERS;
  		event->queue = SNDRV_SEQ_QUEUE_DIRECT;
  	} else
  #ifdef SUPPORT_BROADCAST
  		if (event->queue == SNDRV_SEQ_ADDRESS_BROADCAST) {
  			event->dest.client = SNDRV_SEQ_ADDRESS_BROADCAST;
  			event->queue = SNDRV_SEQ_QUEUE_DIRECT;
  		}
  #endif
  	if (event->dest.client == SNDRV_SEQ_ADDRESS_SUBSCRIBERS) {
  		/* check presence of source port */
  		struct snd_seq_client_port *src_port = snd_seq_port_use_ptr(client, event->source.port);
  		if (src_port == NULL)
  			return -EINVAL;
  		snd_seq_port_unlock(src_port);
  	}
  
  	/* direct event processing without enqueued */
  	if (snd_seq_ev_is_direct(event)) {
  		if (event->type == SNDRV_SEQ_EVENT_NOTE)
  			return -EINVAL; /* this event must be enqueued! */
  		return snd_seq_deliver_event(client, event, atomic, hop);
  	}
  
  	/* Not direct, normal queuing */
  	if (snd_seq_queue_is_used(event->queue, client->number) <= 0)
  		return -EINVAL;  /* invalid queue */
  	if (! snd_seq_write_pool_allocated(client))
  		return -ENXIO; /* queue is not allocated */
  
  	/* allocate an event cell */
  	err = snd_seq_event_dup(client->pool, event, &cell, !blocking || atomic, file);
  	if (err < 0)
  		return err;
  
  	/* we got a cell. enqueue it. */
  	if ((err = snd_seq_enqueue_event(cell, atomic, hop)) < 0) {
  		snd_seq_cell_free(cell);
  		return err;
  	}
  
  	return 0;
  }
  
  /*
   * check validity of event type and data length.
   * return non-zero if invalid.
   */
  static int check_event_type_and_length(struct snd_seq_event *ev)
  {
  	switch (snd_seq_ev_length_type(ev)) {
  	case SNDRV_SEQ_EVENT_LENGTH_FIXED:
  		if (snd_seq_ev_is_variable_type(ev))
  			return -EINVAL;
  		break;
  	case SNDRV_SEQ_EVENT_LENGTH_VARIABLE:
  		if (! snd_seq_ev_is_variable_type(ev) ||
  		    (ev->data.ext.len & ~SNDRV_SEQ_EXT_MASK) >= SNDRV_SEQ_MAX_EVENT_LEN)
  			return -EINVAL;
  		break;
  	case SNDRV_SEQ_EVENT_LENGTH_VARUSR:
  		if (! snd_seq_ev_is_direct(ev))
  			return -EINVAL;
  		break;
  	}
  	return 0;
  }
  
  /* handle write() */
  /* possible error values:
   *	-ENXIO	invalid client or file open mode
   *	-ENOMEM	malloc failed
   *	-EFAULT	seg. fault during copy from user space
   *	-EINVAL	invalid event
   *	-EAGAIN	no space in output pool
   *	-EINTR	interrupts while sleep
   *	-EMLINK	too many hops
   *	others	depends on return value from driver callback
   */
  static ssize_t snd_seq_write(struct file *file, const char __user *buf,
  			     size_t count, loff_t *offset)
  {
  	struct snd_seq_client *client = file->private_data;
  	int written = 0, len;
  	int err = -EINVAL;
  	struct snd_seq_event event;
  
  	if (!(snd_seq_file_flags(file) & SNDRV_SEQ_LFLG_OUTPUT))
  		return -ENXIO;
  
  	/* check client structures are in place */
  	if (snd_BUG_ON(!client))
  		return -ENXIO;
  
  	if (!client->accept_output || client->pool == NULL)
  		return -ENXIO;
  
  	/* allocate the pool now if the pool is not allocated yet */
  	if (client->pool->size > 0 && !snd_seq_write_pool_allocated(client)) {
  		if (snd_seq_pool_init(client->pool) < 0)
  			return -ENOMEM;
  	}
  
  	/* only process whole events */
  	while (count >= sizeof(struct snd_seq_event)) {
  		/* Read in the event header from the user */
  		len = sizeof(event);
  		if (copy_from_user(&event, buf, len)) {
  			err = -EFAULT;
  			break;
  		}
  		event.source.client = client->number;	/* fill in client number */
  		/* Check for extension data length */
  		if (check_event_type_and_length(&event)) {
  			err = -EINVAL;
  			break;
  		}
  
  		/* check for special events */
  		if (event.type == SNDRV_SEQ_EVENT_NONE)
  			goto __skip_event;
  		else if (snd_seq_ev_is_reserved(&event)) {
  			err = -EINVAL;
  			break;
  		}
  
  		if (snd_seq_ev_is_variable(&event)) {
  			int extlen = event.data.ext.len & ~SNDRV_SEQ_EXT_MASK;
  			if ((size_t)(extlen + len) > count) {
  				/* back out, will get an error this time or next */
  				err = -EINVAL;
  				break;
  			}
  			/* set user space pointer */
  			event.data.ext.len = extlen | SNDRV_SEQ_EXT_USRPTR;
  			event.data.ext.ptr = (char __force *)buf
  						+ sizeof(struct snd_seq_event);
  			len += extlen; /* increment data length */
  		} else {
  #ifdef CONFIG_COMPAT
  			if (client->convert32 && snd_seq_ev_is_varusr(&event)) {
  				void *ptr = (void __force *)compat_ptr(event.data.raw32.d[1]);
  				event.data.ext.ptr = ptr;
  			}
  #endif
  		}
  
  		/* ok, enqueue it */
  		err = snd_seq_client_enqueue_event(client, &event, file,
  						   !(file->f_flags & O_NONBLOCK),
  						   0, 0);
  		if (err < 0)
  			break;
  
  	__skip_event:
  		/* Update pointers and counts */
  		count -= len;
  		buf += len;
  		written += len;
  	}
  
  	return written ? written : err;
  }
  
  /*
   * handle polling
   */
  static unsigned int snd_seq_poll(struct file *file, poll_table * wait)
  {
  	struct snd_seq_client *client = file->private_data;
  	unsigned int mask = 0;
  
  	/* check client structures are in place */
  	if (snd_BUG_ON(!client))
  		return -ENXIO;
  
  	if ((snd_seq_file_flags(file) & SNDRV_SEQ_LFLG_INPUT) &&
  	    client->data.user.fifo) {
  
  		/* check if data is available in the outqueue */
  		if (snd_seq_fifo_poll_wait(client->data.user.fifo, file, wait))
  			mask |= POLLIN | POLLRDNORM;
  	}
  
  	if (snd_seq_file_flags(file) & SNDRV_SEQ_LFLG_OUTPUT) {
  
  		/* check if data is available in the pool */
  		if (!snd_seq_write_pool_allocated(client) ||
  		    snd_seq_pool_poll_wait(client->pool, file, wait))
  			mask |= POLLOUT | POLLWRNORM;
  	}
  
  	return mask;
  }
  
  /*-----------------------------------------------------*/
  
  /* SYSTEM_INFO ioctl() */
  static int snd_seq_ioctl_system_info(struct snd_seq_client *client, void __user *arg)
  {
  	struct snd_seq_system_info info;
  
  	memset(&info, 0, sizeof(info));
  	/* fill the info fields */
  	info.queues = SNDRV_SEQ_MAX_QUEUES;
  	info.clients = SNDRV_SEQ_MAX_CLIENTS;
  	info.ports = 256;	/* fixed limit */
  	info.channels = 256;	/* fixed limit */
  	info.cur_clients = client_usage.cur;
  	info.cur_queues = snd_seq_queue_get_cur_queues();
  
  	if (copy_to_user(arg, &info, sizeof(info)))
  		return -EFAULT;
  	return 0;
  }
  
  /* RUNNING_MODE ioctl() */
  static int snd_seq_ioctl_running_mode(struct snd_seq_client *client, void __user *arg)
  {
  	struct snd_seq_running_info info;
  	struct snd_seq_client *cptr;
  	int err = 0;
  
  	if (copy_from_user(&info, arg, sizeof(info)))
  		return -EFAULT;
  
  	/* requested client number */
  	cptr = snd_seq_client_use_ptr(info.client);
  	if (cptr == NULL)
  		return -ENOENT;		/* don't change !!! */
  
  #ifdef SNDRV_BIG_ENDIAN
  	if (! info.big_endian) {
  		err = -EINVAL;
  		goto __err;
  	}
  #else
  	if (info.big_endian) {
  		err = -EINVAL;
  		goto __err;
  	}
  
  #endif
  	if (info.cpu_mode > sizeof(long)) {
  		err = -EINVAL;
  		goto __err;
  	}
  	cptr->convert32 = (info.cpu_mode < sizeof(long));
   __err:
  	snd_seq_client_unlock(cptr);
  	return err;
  }
  
  /* CLIENT_INFO ioctl() */
  static void get_client_info(struct snd_seq_client *cptr,
  			    struct snd_seq_client_info *info)
  {
  	info->client = cptr->number;
  
  	/* fill the info fields */
  	info->type = cptr->type;
  	strcpy(info->name, cptr->name);
  	info->filter = cptr->filter;
  	info->event_lost = cptr->event_lost;
  	memcpy(info->event_filter, cptr->event_filter, 32);
  	info->num_ports = cptr->num_ports;
  	memset(info->reserved, 0, sizeof(info->reserved));
  }
  
  static int snd_seq_ioctl_get_client_info(struct snd_seq_client *client,
  					 void __user *arg)
  {
  	struct snd_seq_client *cptr;
  	struct snd_seq_client_info client_info;
  
  	if (copy_from_user(&client_info, arg, sizeof(client_info)))
  		return -EFAULT;
  
  	/* requested client number */
  	cptr = snd_seq_client_use_ptr(client_info.client);
  	if (cptr == NULL)
  		return -ENOENT;		/* don't change !!! */
  
  	get_client_info(cptr, &client_info);
  	snd_seq_client_unlock(cptr);
  
  	if (copy_to_user(arg, &client_info, sizeof(client_info)))
  		return -EFAULT;
  	return 0;
  }
  
  /* CLIENT_INFO ioctl() */
  static int snd_seq_ioctl_set_client_info(struct snd_seq_client *client,
  					 void __user *arg)
  {
  	struct snd_seq_client_info client_info;
  
  	if (copy_from_user(&client_info, arg, sizeof(client_info)))
  		return -EFAULT;
  
  	/* it is not allowed to set the info fields for an another client */
  	if (client->number != client_info.client)
  		return -EPERM;
  	/* also client type must be set now */
  	if (client->type != client_info.type)
  		return -EINVAL;
  
  	/* fill the info fields */
  	if (client_info.name[0])
  		strlcpy(client->name, client_info.name, sizeof(client->name));
  
  	client->filter = client_info.filter;
  	client->event_lost = client_info.event_lost;
  	memcpy(client->event_filter, client_info.event_filter, 32);
  
  	return 0;
  }
  
  /*
   * CREATE PORT ioctl()
   */
  static int snd_seq_ioctl_create_port(struct snd_seq_client *client,
  				     void __user *arg)
  {
  	struct snd_seq_client_port *port;
  	struct snd_seq_port_info info;
  	struct snd_seq_port_callback *callback;
  
  	if (copy_from_user(&info, arg, sizeof(info)))
  		return -EFAULT;
  
  	/* it is not allowed to create the port for an another client */
  	if (info.addr.client != client->number)
  		return -EPERM;
  
  	port = snd_seq_create_port(client, (info.flags & SNDRV_SEQ_PORT_FLG_GIVEN_PORT) ? info.addr.port : -1);
  	if (port == NULL)
  		return -ENOMEM;
  
  	if (client->type == USER_CLIENT && info.kernel) {
  		snd_seq_delete_port(client, port->addr.port);
  		return -EINVAL;
  	}
  	if (client->type == KERNEL_CLIENT) {
  		if ((callback = info.kernel) != NULL) {
  			if (callback->owner)
  				port->owner = callback->owner;
  			port->private_data = callback->private_data;
  			port->private_free = callback->private_free;
  			port->callback_all = callback->callback_all;
  			port->event_input = callback->event_input;
  			port->c_src.open = callback->subscribe;
  			port->c_src.close = callback->unsubscribe;
  			port->c_dest.open = callback->use;
  			port->c_dest.close = callback->unuse;
  		}
  	}
  
  	info.addr = port->addr;
  
  	snd_seq_set_port_info(port, &info);
  	snd_seq_system_client_ev_port_start(port->addr.client, port->addr.port);
  
  	if (copy_to_user(arg, &info, sizeof(info)))
  		return -EFAULT;
  
  	return 0;
  }
  
  /*
   * DELETE PORT ioctl()
   */
  static int snd_seq_ioctl_delete_port(struct snd_seq_client *client,
  				     void __user *arg)
  {
  	struct snd_seq_port_info info;
  	int err;
  
  	/* set passed parameters */
  	if (copy_from_user(&info, arg, sizeof(info)))
  		return -EFAULT;
  
  	/* it is not allowed to remove the port for an another client */
  	if (info.addr.client != client->number)
  		return -EPERM;
  
  	err = snd_seq_delete_port(client, info.addr.port);
  	if (err >= 0)
  		snd_seq_system_client_ev_port_exit(client->number, info.addr.port);
  	return err;
  }
  
  /*
   * GET_PORT_INFO ioctl() (on any client)
   */
  static int snd_seq_ioctl_get_port_info(struct snd_seq_client *client,
  				       void __user *arg)
  {
  	struct snd_seq_client *cptr;
  	struct snd_seq_client_port *port;
  	struct snd_seq_port_info info;
  
  	if (copy_from_user(&info, arg, sizeof(info)))
  		return -EFAULT;
  	cptr = snd_seq_client_use_ptr(info.addr.client);
  	if (cptr == NULL)
  		return -ENXIO;
  
  	port = snd_seq_port_use_ptr(cptr, info.addr.port);
  	if (port == NULL) {
  		snd_seq_client_unlock(cptr);
  		return -ENOENT;			/* don't change */
  	}
  
  	/* get port info */
  	snd_seq_get_port_info(port, &info);
  	snd_seq_port_unlock(port);
  	snd_seq_client_unlock(cptr);
  
  	if (copy_to_user(arg, &info, sizeof(info)))
  		return -EFAULT;
  	return 0;
  }
  
  /*
   * SET_PORT_INFO ioctl() (only ports on this/own client)
   */
  static int snd_seq_ioctl_set_port_info(struct snd_seq_client *client,
  				       void __user *arg)
  {
  	struct snd_seq_client_port *port;
  	struct snd_seq_port_info info;
  
  	if (copy_from_user(&info, arg, sizeof(info)))
  		return -EFAULT;
  
  	if (info.addr.client != client->number) /* only set our own ports ! */
  		return -EPERM;
  	port = snd_seq_port_use_ptr(client, info.addr.port);
  	if (port) {
  		snd_seq_set_port_info(port, &info);
  		snd_seq_port_unlock(port);
  	}
  	return 0;
  }
  
  /*
   * port subscription (connection)
   */
  #define PERM_RD		(SNDRV_SEQ_PORT_CAP_READ|SNDRV_SEQ_PORT_CAP_SUBS_READ)
  #define PERM_WR		(SNDRV_SEQ_PORT_CAP_WRITE|SNDRV_SEQ_PORT_CAP_SUBS_WRITE)
  
  static int check_subscription_permission(struct snd_seq_client *client,
  					 struct snd_seq_client_port *sport,
  					 struct snd_seq_client_port *dport,
  					 struct snd_seq_port_subscribe *subs)
  {
  	if (client->number != subs->sender.client &&
  	    client->number != subs->dest.client) {
  		/* connection by third client - check export permission */
  		if (check_port_perm(sport, SNDRV_SEQ_PORT_CAP_NO_EXPORT))
  			return -EPERM;
  		if (check_port_perm(dport, SNDRV_SEQ_PORT_CAP_NO_EXPORT))
  			return -EPERM;
  	}
  
  	/* check read permission */
  	/* if sender or receiver is the subscribing client itself,
  	 * no permission check is necessary
  	 */
  	if (client->number != subs->sender.client) {
  		if (! check_port_perm(sport, PERM_RD))
  			return -EPERM;
  	}
  	/* check write permission */
  	if (client->number != subs->dest.client) {
  		if (! check_port_perm(dport, PERM_WR))
  			return -EPERM;
  	}
  	return 0;
  }
  
  /*
   * send an subscription notify event to user client:
   * client must be user client.
   */
  int snd_seq_client_notify_subscription(int client, int port,
  				       struct snd_seq_port_subscribe *info,
  				       int evtype)
  {
  	struct snd_seq_event event;
  
  	memset(&event, 0, sizeof(event));
  	event.type = evtype;
  	event.data.connect.dest = info->dest;
  	event.data.connect.sender = info->sender;
  
  	return snd_seq_system_notify(client, port, &event);  /* non-atomic */
  }
  
  /*
   * add to port's subscription list IOCTL interface
   */
  static int snd_seq_ioctl_subscribe_port(struct snd_seq_client *client,
  					void __user *arg)
  {
  	int result = -EINVAL;
  	struct snd_seq_client *receiver = NULL, *sender = NULL;
  	struct snd_seq_client_port *sport = NULL, *dport = NULL;
  	struct snd_seq_port_subscribe subs;
  
  	if (copy_from_user(&subs, arg, sizeof(subs)))
  		return -EFAULT;
  
  	if ((receiver = snd_seq_client_use_ptr(subs.dest.client)) == NULL)
  		goto __end;
  	if ((sender = snd_seq_client_use_ptr(subs.sender.client)) == NULL)
  		goto __end;
  	if ((sport = snd_seq_port_use_ptr(sender, subs.sender.port)) == NULL)
  		goto __end;
  	if ((dport = snd_seq_port_use_ptr(receiver, subs.dest.port)) == NULL)
  		goto __end;
  
  	result = check_subscription_permission(client, sport, dport, &subs);
  	if (result < 0)
  		goto __end;
  
  	/* connect them */
  	result = snd_seq_port_connect(client, sender, sport, receiver, dport, &subs);
  	if (! result) /* broadcast announce */
  		snd_seq_client_notify_subscription(SNDRV_SEQ_ADDRESS_SUBSCRIBERS, 0,
  						   &subs, SNDRV_SEQ_EVENT_PORT_SUBSCRIBED);
        __end:
        	if (sport)
  		snd_seq_port_unlock(sport);
  	if (dport)
  		snd_seq_port_unlock(dport);
  	if (sender)
  		snd_seq_client_unlock(sender);
  	if (receiver)
  		snd_seq_client_unlock(receiver);
  	return result;
  }
  
  /*
   * remove from port's subscription list
   */
  static int snd_seq_ioctl_unsubscribe_port(struct snd_seq_client *client,
  					  void __user *arg)
  {
  	int result = -ENXIO;
  	struct snd_seq_client *receiver = NULL, *sender = NULL;
  	struct snd_seq_client_port *sport = NULL, *dport = NULL;
  	struct snd_seq_port_subscribe subs;
  
  	if (copy_from_user(&subs, arg, sizeof(subs)))
  		return -EFAULT;
  
  	if ((receiver = snd_seq_client_use_ptr(subs.dest.client)) == NULL)
  		goto __end;
  	if ((sender = snd_seq_client_use_ptr(subs.sender.client)) == NULL)
  		goto __end;
  	if ((sport = snd_seq_port_use_ptr(sender, subs.sender.port)) == NULL)
  		goto __end;
  	if ((dport = snd_seq_port_use_ptr(receiver, subs.dest.port)) == NULL)
  		goto __end;
  
  	result = check_subscription_permission(client, sport, dport, &subs);
  	if (result < 0)
  		goto __end;
  
  	result = snd_seq_port_disconnect(client, sender, sport, receiver, dport, &subs);
  	if (! result) /* broadcast announce */
  		snd_seq_client_notify_subscription(SNDRV_SEQ_ADDRESS_SUBSCRIBERS, 0,
  						   &subs, SNDRV_SEQ_EVENT_PORT_UNSUBSCRIBED);
        __end:
        	if (sport)
  		snd_seq_port_unlock(sport);
  	if (dport)
  		snd_seq_port_unlock(dport);
  	if (sender)
  		snd_seq_client_unlock(sender);
  	if (receiver)
  		snd_seq_client_unlock(receiver);
  	return result;
  }
  
  /* CREATE_QUEUE ioctl() */
  static int snd_seq_ioctl_create_queue(struct snd_seq_client *client,
  				      void __user *arg)
  {
  	struct snd_seq_queue_info info;
  	int result;
  	struct snd_seq_queue *q;
  
  	if (copy_from_user(&info, arg, sizeof(info)))
  		return -EFAULT;
  
  	result = snd_seq_queue_alloc(client->number, info.locked, info.flags);
  	if (result < 0)
  		return result;
  
  	q = queueptr(result);
  	if (q == NULL)
  		return -EINVAL;
  
  	info.queue = q->queue;
  	info.locked = q->locked;
  	info.owner = q->owner;
  
  	/* set queue name */
  	if (! info.name[0])
  		snprintf(info.name, sizeof(info.name), "Queue-%d", q->queue);
  	strlcpy(q->name, info.name, sizeof(q->name));
  	queuefree(q);
  
  	if (copy_to_user(arg, &info, sizeof(info)))
  		return -EFAULT;
  
  	return 0;
  }
  
  /* DELETE_QUEUE ioctl() */
  static int snd_seq_ioctl_delete_queue(struct snd_seq_client *client,
  				      void __user *arg)
  {
  	struct snd_seq_queue_info info;
  
  	if (copy_from_user(&info, arg, sizeof(info)))
  		return -EFAULT;
  
  	return snd_seq_queue_delete(client->number, info.queue);
  }
  
  /* GET_QUEUE_INFO ioctl() */
  static int snd_seq_ioctl_get_queue_info(struct snd_seq_client *client,
  					void __user *arg)
  {
  	struct snd_seq_queue_info info;
  	struct snd_seq_queue *q;
  
  	if (copy_from_user(&info, arg, sizeof(info)))
  		return -EFAULT;
  
  	q = queueptr(info.queue);
  	if (q == NULL)
  		return -EINVAL;
  
  	memset(&info, 0, sizeof(info));
  	info.queue = q->queue;
  	info.owner = q->owner;
  	info.locked = q->locked;
  	strlcpy(info.name, q->name, sizeof(info.name));
  	queuefree(q);
  
  	if (copy_to_user(arg, &info, sizeof(info)))
  		return -EFAULT;
  
  	return 0;
  }
  
  /* SET_QUEUE_INFO ioctl() */
  static int snd_seq_ioctl_set_queue_info(struct snd_seq_client *client,
  					void __user *arg)
  {
  	struct snd_seq_queue_info info;
  	struct snd_seq_queue *q;
  
  	if (copy_from_user(&info, arg, sizeof(info)))
  		return -EFAULT;
  
  	if (info.owner != client->number)
  		return -EINVAL;
  
  	/* change owner/locked permission */
  	if (snd_seq_queue_check_access(info.queue, client->number)) {
  		if (snd_seq_queue_set_owner(info.queue, client->number, info.locked) < 0)
  			return -EPERM;
  		if (info.locked)
  			snd_seq_queue_use(info.queue, client->number, 1);
  	} else {
  		return -EPERM;
  	}
  
  	q = queueptr(info.queue);
  	if (! q)
  		return -EINVAL;
  	if (q->owner != client->number) {
  		queuefree(q);
  		return -EPERM;
  	}
  	strlcpy(q->name, info.name, sizeof(q->name));
  	queuefree(q);
  
  	return 0;
  }
  
  /* GET_NAMED_QUEUE ioctl() */
  static int snd_seq_ioctl_get_named_queue(struct snd_seq_client *client, void __user *arg)
  {
  	struct snd_seq_queue_info info;
  	struct snd_seq_queue *q;
  
  	if (copy_from_user(&info, arg, sizeof(info)))
  		return -EFAULT;
  
  	q = snd_seq_queue_find_name(info.name);
  	if (q == NULL)
  		return -EINVAL;
  	info.queue = q->queue;
  	info.owner = q->owner;
  	info.locked = q->locked;
  	queuefree(q);
  
  	if (copy_to_user(arg, &info, sizeof(info)))
  		return -EFAULT;
  
  	return 0;
  }
  
  /* GET_QUEUE_STATUS ioctl() */
  static int snd_seq_ioctl_get_queue_status(struct snd_seq_client *client,
  					  void __user *arg)
  {
  	struct snd_seq_queue_status status;
  	struct snd_seq_queue *queue;
  	struct snd_seq_timer *tmr;
  
  	if (copy_from_user(&status, arg, sizeof(status)))
  		return -EFAULT;
  
  	queue = queueptr(status.queue);
  	if (queue == NULL)
  		return -EINVAL;
  	memset(&status, 0, sizeof(status));
  	status.queue = queue->queue;
  
  	tmr = queue->timer;
  	status.events = queue->tickq->cells + queue->timeq->cells;
  
  	status.time = snd_seq_timer_get_cur_time(tmr);
  	status.tick = snd_seq_timer_get_cur_tick(tmr);
  
  	status.running = tmr->running;
  
  	status.flags = queue->flags;
  	queuefree(queue);
  
  	if (copy_to_user(arg, &status, sizeof(status)))
  		return -EFAULT;
  	return 0;
  }
  
  /* GET_QUEUE_TEMPO ioctl() */
  static int snd_seq_ioctl_get_queue_tempo(struct snd_seq_client *client,
  					 void __user *arg)
  {
  	struct snd_seq_queue_tempo tempo;
  	struct snd_seq_queue *queue;
  	struct snd_seq_timer *tmr;
  
  	if (copy_from_user(&tempo, arg, sizeof(tempo)))
  		return -EFAULT;
  
  	queue = queueptr(tempo.queue);
  	if (queue == NULL)
  		return -EINVAL;
  	memset(&tempo, 0, sizeof(tempo));
  	tempo.queue = queue->queue;
  
  	tmr = queue->timer;
  
  	tempo.tempo = tmr->tempo;
  	tempo.ppq = tmr->ppq;
  	tempo.skew_value = tmr->skew;
  	tempo.skew_base = tmr->skew_base;
  	queuefree(queue);
  
  	if (copy_to_user(arg, &tempo, sizeof(tempo)))
  		return -EFAULT;
  	return 0;
  }
  
  /* SET_QUEUE_TEMPO ioctl() */
  int snd_seq_set_queue_tempo(int client, struct snd_seq_queue_tempo *tempo)
  {
  	if (!snd_seq_queue_check_access(tempo->queue, client))
  		return -EPERM;
  	return snd_seq_queue_timer_set_tempo(tempo->queue, client, tempo);
  }
  
  EXPORT_SYMBOL(snd_seq_set_queue_tempo);
  
  static int snd_seq_ioctl_set_queue_tempo(struct snd_seq_client *client,
  					 void __user *arg)
  {
  	int result;
  	struct snd_seq_queue_tempo tempo;
  
  	if (copy_from_user(&tempo, arg, sizeof(tempo)))
  		return -EFAULT;
  
  	result = snd_seq_set_queue_tempo(client->number, &tempo);
  	return result < 0 ? result : 0;
  }
  
  /* GET_QUEUE_TIMER ioctl() */
  static int snd_seq_ioctl_get_queue_timer(struct snd_seq_client *client,
  					 void __user *arg)
  {
  	struct snd_seq_queue_timer timer;
  	struct snd_seq_queue *queue;
  	struct snd_seq_timer *tmr;
  
  	if (copy_from_user(&timer, arg, sizeof(timer)))
  		return -EFAULT;
  
  	queue = queueptr(timer.queue);
  	if (queue == NULL)
  		return -EINVAL;
  
  	if (mutex_lock_interruptible(&queue->timer_mutex)) {
  		queuefree(queue);
  		return -ERESTARTSYS;
  	}
  	tmr = queue->timer;
  	memset(&timer, 0, sizeof(timer));
  	timer.queue = queue->queue;
  
  	timer.type = tmr->type;
  	if (tmr->type == SNDRV_SEQ_TIMER_ALSA) {
  		timer.u.alsa.id = tmr->alsa_id;
  		timer.u.alsa.resolution = tmr->preferred_resolution;
  	}
  	mutex_unlock(&queue->timer_mutex);
  	queuefree(queue);
  
  	if (copy_to_user(arg, &timer, sizeof(timer)))
  		return -EFAULT;
  	return 0;
  }
  
  /* SET_QUEUE_TIMER ioctl() */
  static int snd_seq_ioctl_set_queue_timer(struct snd_seq_client *client,
  					 void __user *arg)
  {
  	int result = 0;
  	struct snd_seq_queue_timer timer;
  
  	if (copy_from_user(&timer, arg, sizeof(timer)))
  		return -EFAULT;
  
  	if (timer.type != SNDRV_SEQ_TIMER_ALSA)
  		return -EINVAL;
  
  	if (snd_seq_queue_check_access(timer.queue, client->number)) {
  		struct snd_seq_queue *q;
  		struct snd_seq_timer *tmr;
  
  		q = queueptr(timer.queue);
  		if (q == NULL)
  			return -ENXIO;
  		if (mutex_lock_interruptible(&q->timer_mutex)) {
  			queuefree(q);
  			return -ERESTARTSYS;
  		}
  		tmr = q->timer;
  		snd_seq_queue_timer_close(timer.queue);
  		tmr->type = timer.type;
  		if (tmr->type == SNDRV_SEQ_TIMER_ALSA) {
  			tmr->alsa_id = timer.u.alsa.id;
  			tmr->preferred_resolution = timer.u.alsa.resolution;
  		}
  		result = snd_seq_queue_timer_open(timer.queue);
  		mutex_unlock(&q->timer_mutex);
  		queuefree(q);
  	} else {
  		return -EPERM;
  	}
  
  	return result;
  }
  
  /* GET_QUEUE_CLIENT ioctl() */
  static int snd_seq_ioctl_get_queue_client(struct snd_seq_client *client,
  					  void __user *arg)
  {
  	struct snd_seq_queue_client info;
  	int used;
  
  	if (copy_from_user(&info, arg, sizeof(info)))
  		return -EFAULT;
  
  	used = snd_seq_queue_is_used(info.queue, client->number);
  	if (used < 0)
  		return -EINVAL;
  	info.used = used;
  	info.client = client->number;
  
  	if (copy_to_user(arg, &info, sizeof(info)))
  		return -EFAULT;
  	return 0;
  }
  
  /* SET_QUEUE_CLIENT ioctl() */
  static int snd_seq_ioctl_set_queue_client(struct snd_seq_client *client,
  					  void __user *arg)
  {
  	int err;
  	struct snd_seq_queue_client info;
  
  	if (copy_from_user(&info, arg, sizeof(info)))
  		return -EFAULT;
  
  	if (info.used >= 0) {
  		err = snd_seq_queue_use(info.queue, client->number, info.used);
  		if (err < 0)
  			return err;
  	}
  
  	return snd_seq_ioctl_get_queue_client(client, arg);
  }
  
  /* GET_CLIENT_POOL ioctl() */
  static int snd_seq_ioctl_get_client_pool(struct snd_seq_client *client,
  					 void __user *arg)
  {
  	struct snd_seq_client_pool info;
  	struct snd_seq_client *cptr;
  
  	if (copy_from_user(&info, arg, sizeof(info)))
  		return -EFAULT;
  
  	cptr = snd_seq_client_use_ptr(info.client);
  	if (cptr == NULL)
  		return -ENOENT;
  	memset(&info, 0, sizeof(info));
  	info.output_pool = cptr->pool->size;
  	info.output_room = cptr->pool->room;
  	info.output_free = info.output_pool;
  	info.output_free = snd_seq_unused_cells(cptr->pool);
  	if (cptr->type == USER_CLIENT) {
  		info.input_pool = cptr->data.user.fifo_pool_size;
  		info.input_free = info.input_pool;
  		if (cptr->data.user.fifo)
  			info.input_free = snd_seq_unused_cells(cptr->data.user.fifo->pool);
  	} else {
  		info.input_pool = 0;
  		info.input_free = 0;
  	}
  	snd_seq_client_unlock(cptr);
  
  	if (copy_to_user(arg, &info, sizeof(info)))
  		return -EFAULT;
  	return 0;
  }
  
  /* SET_CLIENT_POOL ioctl() */
  static int snd_seq_ioctl_set_client_pool(struct snd_seq_client *client,
  					 void __user *arg)
  {
  	struct snd_seq_client_pool info;
  	int rc;
  
  	if (copy_from_user(&info, arg, sizeof(info)))
  		return -EFAULT;
  
  	if (client->number != info.client)
  		return -EINVAL; /* can't change other clients */
  
  	if (info.output_pool >= 1 && info.output_pool <= SNDRV_SEQ_MAX_EVENTS &&
  	    (! snd_seq_write_pool_allocated(client) ||
  	     info.output_pool != client->pool->size)) {
  		if (snd_seq_write_pool_allocated(client)) {
  			/* remove all existing cells */
  			snd_seq_queue_client_leave_cells(client->number);
  			snd_seq_pool_done(client->pool);
  		}
  		client->pool->size = info.output_pool;
  		rc = snd_seq_pool_init(client->pool);
  		if (rc < 0)
  			return rc;
  	}
  	if (client->type == USER_CLIENT && client->data.user.fifo != NULL &&
  	    info.input_pool >= 1 &&
  	    info.input_pool <= SNDRV_SEQ_MAX_CLIENT_EVENTS &&
  	    info.input_pool != client->data.user.fifo_pool_size) {
  		/* change pool size */
  		rc = snd_seq_fifo_resize(client->data.user.fifo, info.input_pool);
  		if (rc < 0)
  			return rc;
  		client->data.user.fifo_pool_size = info.input_pool;
  	}
  	if (info.output_room >= 1 &&
  	    info.output_room <= client->pool->size) {
  		client->pool->room  = info.output_room;
  	}
  
  	return snd_seq_ioctl_get_client_pool(client, arg);
  }
  
  /* REMOVE_EVENTS ioctl() */
  static int snd_seq_ioctl_remove_events(struct snd_seq_client *client,
  				       void __user *arg)
  {
  	struct snd_seq_remove_events info;
  
  	if (copy_from_user(&info, arg, sizeof(info)))
  		return -EFAULT;
  
  	/*
  	 * Input mostly not implemented XXX.
  	 */
  	if (info.remove_mode & SNDRV_SEQ_REMOVE_INPUT) {
  		/*
  		 * No restrictions so for a user client we can clear
  		 * the whole fifo
  		 */
  		if (client->type == USER_CLIENT)
  			snd_seq_fifo_clear(client->data.user.fifo);
  	}
  
  	if (info.remove_mode & SNDRV_SEQ_REMOVE_OUTPUT)
  		snd_seq_queue_remove_cells(client->number, &info);
  
  	return 0;
  }
  
  /*
   * get subscription info
   */
  static int snd_seq_ioctl_get_subscription(struct snd_seq_client *client,
  					  void __user *arg)
  {
  	int result;
  	struct snd_seq_client *sender = NULL;
  	struct snd_seq_client_port *sport = NULL;
  	struct snd_seq_port_subscribe subs;
  	struct snd_seq_subscribers *p;
  
  	if (copy_from_user(&subs, arg, sizeof(subs)))
  		return -EFAULT;
  
  	result = -EINVAL;
  	if ((sender = snd_seq_client_use_ptr(subs.sender.client)) == NULL)
  		goto __end;
  	if ((sport = snd_seq_port_use_ptr(sender, subs.sender.port)) == NULL)
  		goto __end;
  	p = snd_seq_port_get_subscription(&sport->c_src, &subs.dest);
  	if (p) {
  		result = 0;
  		subs = p->info;
  	} else
  		result = -ENOENT;
  
        __end:
        	if (sport)
  		snd_seq_port_unlock(sport);
  	if (sender)
  		snd_seq_client_unlock(sender);
  	if (result >= 0) {
  		if (copy_to_user(arg, &subs, sizeof(subs)))
  			return -EFAULT;
  	}
  	return result;
  }
  
  /*
   * get subscription info - check only its presence
   */
  static int snd_seq_ioctl_query_subs(struct snd_seq_client *client,
  				    void __user *arg)
  {
  	int result = -ENXIO;
  	struct snd_seq_client *cptr = NULL;
  	struct snd_seq_client_port *port = NULL;
  	struct snd_seq_query_subs subs;
  	struct snd_seq_port_subs_info *group;
  	struct list_head *p;
  	int i;
  
  	if (copy_from_user(&subs, arg, sizeof(subs)))
  		return -EFAULT;
  
  	if ((cptr = snd_seq_client_use_ptr(subs.root.client)) == NULL)
  		goto __end;
  	if ((port = snd_seq_port_use_ptr(cptr, subs.root.port)) == NULL)
  		goto __end;
  
  	switch (subs.type) {
  	case SNDRV_SEQ_QUERY_SUBS_READ:
  		group = &port->c_src;
  		break;
  	case SNDRV_SEQ_QUERY_SUBS_WRITE:
  		group = &port->c_dest;
  		break;
  	default:
  		goto __end;
  	}
  
  	down_read(&group->list_mutex);
  	/* search for the subscriber */
  	subs.num_subs = group->count;
  	i = 0;
  	result = -ENOENT;
  	list_for_each(p, &group->list_head) {
  		if (i++ == subs.index) {
  			/* found! */
  			struct snd_seq_subscribers *s;
  			if (subs.type == SNDRV_SEQ_QUERY_SUBS_READ) {
  				s = list_entry(p, struct snd_seq_subscribers, src_list);
  				subs.addr = s->info.dest;
  			} else {
  				s = list_entry(p, struct snd_seq_subscribers, dest_list);
  				subs.addr = s->info.sender;
  			}
  			subs.flags = s->info.flags;
  			subs.queue = s->info.queue;
  			result = 0;
  			break;
  		}
  	}
  	up_read(&group->list_mutex);
  
        __end:
     	if (port)
  		snd_seq_port_unlock(port);
  	if (cptr)
  		snd_seq_client_unlock(cptr);
  	if (result >= 0) {
  		if (copy_to_user(arg, &subs, sizeof(subs)))
  			return -EFAULT;
  	}
  	return result;
  }
  
  /*
   * query next client
   */
  static int snd_seq_ioctl_query_next_client(struct snd_seq_client *client,
  					   void __user *arg)
  {
  	struct snd_seq_client *cptr = NULL;
  	struct snd_seq_client_info info;
  
  	if (copy_from_user(&info, arg, sizeof(info)))
  		return -EFAULT;
  
  	/* search for next client */
  	info.client++;
  	if (info.client < 0)
  		info.client = 0;
  	for (; info.client < SNDRV_SEQ_MAX_CLIENTS; info.client++) {
  		cptr = snd_seq_client_use_ptr(info.client);
  		if (cptr)
  			break; /* found */
  	}
  	if (cptr == NULL)
  		return -ENOENT;
  
  	get_client_info(cptr, &info);
  	snd_seq_client_unlock(cptr);
  
  	if (copy_to_user(arg, &info, sizeof(info)))
  		return -EFAULT;
  	return 0;
  }
  
  /*
   * query next port
   */
  static int snd_seq_ioctl_query_next_port(struct snd_seq_client *client,
  					 void __user *arg)
  {
  	struct snd_seq_client *cptr;
  	struct snd_seq_client_port *port = NULL;
  	struct snd_seq_port_info info;
  
  	if (copy_from_user(&info, arg, sizeof(info)))
  		return -EFAULT;
  	cptr = snd_seq_client_use_ptr(info.addr.client);
  	if (cptr == NULL)
  		return -ENXIO;
  
  	/* search for next port */
  	info.addr.port++;
  	port = snd_seq_port_query_nearest(cptr, &info);
  	if (port == NULL) {
  		snd_seq_client_unlock(cptr);
  		return -ENOENT;
  	}
  
  	/* get port info */
  	info.addr = port->addr;
  	snd_seq_get_port_info(port, &info);
  	snd_seq_port_unlock(port);
  	snd_seq_client_unlock(cptr);
  
  	if (copy_to_user(arg, &info, sizeof(info)))
  		return -EFAULT;
  	return 0;
  }
  
  /* -------------------------------------------------------- */
  
  static struct seq_ioctl_table {
  	unsigned int cmd;
  	int (*func)(struct snd_seq_client *client, void __user * arg);
  } ioctl_tables[] = {
  	{ SNDRV_SEQ_IOCTL_SYSTEM_INFO, snd_seq_ioctl_system_info },
  	{ SNDRV_SEQ_IOCTL_RUNNING_MODE, snd_seq_ioctl_running_mode },
  	{ SNDRV_SEQ_IOCTL_GET_CLIENT_INFO, snd_seq_ioctl_get_client_info },
  	{ SNDRV_SEQ_IOCTL_SET_CLIENT_INFO, snd_seq_ioctl_set_client_info },
  	{ SNDRV_SEQ_IOCTL_CREATE_PORT, snd_seq_ioctl_create_port },
  	{ SNDRV_SEQ_IOCTL_DELETE_PORT, snd_seq_ioctl_delete_port },
  	{ SNDRV_SEQ_IOCTL_GET_PORT_INFO, snd_seq_ioctl_get_port_info },
  	{ SNDRV_SEQ_IOCTL_SET_PORT_INFO, snd_seq_ioctl_set_port_info },
  	{ SNDRV_SEQ_IOCTL_SUBSCRIBE_PORT, snd_seq_ioctl_subscribe_port },
  	{ SNDRV_SEQ_IOCTL_UNSUBSCRIBE_PORT, snd_seq_ioctl_unsubscribe_port },
  	{ SNDRV_SEQ_IOCTL_CREATE_QUEUE, snd_seq_ioctl_create_queue },
  	{ SNDRV_SEQ_IOCTL_DELETE_QUEUE, snd_seq_ioctl_delete_queue },
  	{ SNDRV_SEQ_IOCTL_GET_QUEUE_INFO, snd_seq_ioctl_get_queue_info },
  	{ SNDRV_SEQ_IOCTL_SET_QUEUE_INFO, snd_seq_ioctl_set_queue_info },
  	{ SNDRV_SEQ_IOCTL_GET_NAMED_QUEUE, snd_seq_ioctl_get_named_queue },
  	{ SNDRV_SEQ_IOCTL_GET_QUEUE_STATUS, snd_seq_ioctl_get_queue_status },
  	{ SNDRV_SEQ_IOCTL_GET_QUEUE_TEMPO, snd_seq_ioctl_get_queue_tempo },
  	{ SNDRV_SEQ_IOCTL_SET_QUEUE_TEMPO, snd_seq_ioctl_set_queue_tempo },
  	{ SNDRV_SEQ_IOCTL_GET_QUEUE_TIMER, snd_seq_ioctl_get_queue_timer },
  	{ SNDRV_SEQ_IOCTL_SET_QUEUE_TIMER, snd_seq_ioctl_set_queue_timer },
  	{ SNDRV_SEQ_IOCTL_GET_QUEUE_CLIENT, snd_seq_ioctl_get_queue_client },
  	{ SNDRV_SEQ_IOCTL_SET_QUEUE_CLIENT, snd_seq_ioctl_set_queue_client },
  	{ SNDRV_SEQ_IOCTL_GET_CLIENT_POOL, snd_seq_ioctl_get_client_pool },
  	{ SNDRV_SEQ_IOCTL_SET_CLIENT_POOL, snd_seq_ioctl_set_client_pool },
  	{ SNDRV_SEQ_IOCTL_GET_SUBSCRIPTION, snd_seq_ioctl_get_subscription },
  	{ SNDRV_SEQ_IOCTL_QUERY_NEXT_CLIENT, snd_seq_ioctl_query_next_client },
  	{ SNDRV_SEQ_IOCTL_QUERY_NEXT_PORT, snd_seq_ioctl_query_next_port },
  	{ SNDRV_SEQ_IOCTL_REMOVE_EVENTS, snd_seq_ioctl_remove_events },
  	{ SNDRV_SEQ_IOCTL_QUERY_SUBS, snd_seq_ioctl_query_subs },
  	{ 0, NULL },
  };
  
  static int snd_seq_do_ioctl(struct snd_seq_client *client, unsigned int cmd,
  			    void __user *arg)
  {
  	struct seq_ioctl_table *p;
  
  	switch (cmd) {
  	case SNDRV_SEQ_IOCTL_PVERSION:
  		/* return sequencer version number */
  		return put_user(SNDRV_SEQ_VERSION, (int __user *)arg) ? -EFAULT : 0;
  	case SNDRV_SEQ_IOCTL_CLIENT_ID:
  		/* return the id of this client */
  		return put_user(client->number, (int __user *)arg) ? -EFAULT : 0;
  	}
  
  	if (! arg)
  		return -EFAULT;
  	for (p = ioctl_tables; p->cmd; p++) {
  		if (p->cmd == cmd)
  			return p->func(client, arg);
  	}
  	snd_printd("seq unknown ioctl() 0x%x (type='%c', number=0x%02x)\n",
  		   cmd, _IOC_TYPE(cmd), _IOC_NR(cmd));
  	return -ENOTTY;
  }
  
  static long snd_seq_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
  {
  	struct snd_seq_client *client = file->private_data;
  
  	if (snd_BUG_ON(!client))
  		return -ENXIO;
  
  	return snd_seq_do_ioctl(client, cmd, (void __user *) arg);
  }
  
  #ifdef CONFIG_COMPAT
  #include "seq_compat.c"
  #else
  #define snd_seq_ioctl_compat	NULL
  #endif
  
  /* -------------------------------------------------------- */
  
  /* exported to kernel modules */
  int snd_seq_create_kernel_client(struct snd_card *card, int client_index,
  				 const char *name_fmt, ...)
  {
  	struct snd_seq_client *client;
  	va_list args;
  
  	if (snd_BUG_ON(in_interrupt()))
  		return -EBUSY;
  
  	if (card && client_index >= SNDRV_SEQ_CLIENTS_PER_CARD)
  		return -EINVAL;
  	if (card == NULL && client_index >= SNDRV_SEQ_GLOBAL_CLIENTS)
  		return -EINVAL;
  
  	if (mutex_lock_interruptible(&register_mutex))
  		return -ERESTARTSYS;
  
  	if (card) {
  		client_index += SNDRV_SEQ_GLOBAL_CLIENTS
  			+ card->number * SNDRV_SEQ_CLIENTS_PER_CARD;
  		if (client_index >= SNDRV_SEQ_DYNAMIC_CLIENTS_BEGIN)
  			client_index = -1;
  	}
  
  	/* empty write queue as default */
  	client = seq_create_client1(client_index, 0);
  	if (client == NULL) {
  		mutex_unlock(&register_mutex);
  		return -EBUSY;	/* failure code */
  	}
  	usage_alloc(&client_usage, 1);
  
  	client->accept_input = 1;
  	client->accept_output = 1;
  
  	va_start(args, name_fmt);
  	vsnprintf(client->name, sizeof(client->name), name_fmt, args);
  	va_end(args);
  
  	client->type = KERNEL_CLIENT;
  	mutex_unlock(&register_mutex);
  
  	/* make others aware this new client */
  	snd_seq_system_client_ev_client_start(client->number);
  
  	/* return client number to caller */
  	return client->number;
  }
  
  EXPORT_SYMBOL(snd_seq_create_kernel_client);
  
  /* exported to kernel modules */
  int snd_seq_delete_kernel_client(int client)
  {
  	struct snd_seq_client *ptr;
  
  	if (snd_BUG_ON(in_interrupt()))
  		return -EBUSY;
  
  	ptr = clientptr(client);
  	if (ptr == NULL)
  		return -EINVAL;
  
  	seq_free_client(ptr);
  	kfree(ptr);
  	return 0;
  }
  
  EXPORT_SYMBOL(snd_seq_delete_kernel_client);
  
  /* skeleton to enqueue event, called from snd_seq_kernel_client_enqueue
   * and snd_seq_kernel_client_enqueue_blocking
   */
  static int kernel_client_enqueue(int client, struct snd_seq_event *ev,
  				 struct file *file, int blocking,
  				 int atomic, int hop)
  {
  	struct snd_seq_client *cptr;
  	int result;
  
  	if (snd_BUG_ON(!ev))
  		return -EINVAL;
  
  	if (ev->type == SNDRV_SEQ_EVENT_NONE)
  		return 0; /* ignore this */
  	if (ev->type == SNDRV_SEQ_EVENT_KERNEL_ERROR)
  		return -EINVAL; /* quoted events can't be enqueued */
  
  	/* fill in client number */
  	ev->source.client = client;
  
  	if (check_event_type_and_length(ev))
  		return -EINVAL;
  
  	cptr = snd_seq_client_use_ptr(client);
  	if (cptr == NULL)
  		return -EINVAL;
  
  	if (! cptr->accept_output)
  		result = -EPERM;
  	else /* send it */
  		result = snd_seq_client_enqueue_event(cptr, ev, file, blocking, atomic, hop);
  
  	snd_seq_client_unlock(cptr);
  	return result;
  }
  
  /*
   * exported, called by kernel clients to enqueue events (w/o blocking)
   *
   * RETURN VALUE: zero if succeed, negative if error
   */
  int snd_seq_kernel_client_enqueue(int client, struct snd_seq_event * ev,
  				  int atomic, int hop)
  {
  	return kernel_client_enqueue(client, ev, NULL, 0, atomic, hop);
  }
  
  EXPORT_SYMBOL(snd_seq_kernel_client_enqueue);
  
  /*
   * exported, called by kernel clients to enqueue events (with blocking)
   *
   * RETURN VALUE: zero if succeed, negative if error
   */
  int snd_seq_kernel_client_enqueue_blocking(int client, struct snd_seq_event * ev,
  					   struct file *file,
  					   int atomic, int hop)
  {
  	return kernel_client_enqueue(client, ev, file, 1, atomic, hop);
  }
  
  EXPORT_SYMBOL(snd_seq_kernel_client_enqueue_blocking);
  
  /*
   * exported, called by kernel clients to dispatch events directly to other
   * clients, bypassing the queues.  Event time-stamp will be updated.
   *
   * RETURN VALUE: negative = delivery failed,
   *		 zero, or positive: the number of delivered events
   */
  int snd_seq_kernel_client_dispatch(int client, struct snd_seq_event * ev,
  				   int atomic, int hop)
  {
  	struct snd_seq_client *cptr;
  	int result;
  
  	if (snd_BUG_ON(!ev))
  		return -EINVAL;
  
  	/* fill in client number */
  	ev->queue = SNDRV_SEQ_QUEUE_DIRECT;
  	ev->source.client = client;
  
  	if (check_event_type_and_length(ev))
  		return -EINVAL;
  
  	cptr = snd_seq_client_use_ptr(client);
  	if (cptr == NULL)
  		return -EINVAL;
  
  	if (!cptr->accept_output)
  		result = -EPERM;
  	else
  		result = snd_seq_deliver_event(cptr, ev, atomic, hop);
  
  	snd_seq_client_unlock(cptr);
  	return result;
  }
  
  EXPORT_SYMBOL(snd_seq_kernel_client_dispatch);
  
  /*
   * exported, called by kernel clients to perform same functions as with
   * userland ioctl()
   */
  int snd_seq_kernel_client_ctl(int clientid, unsigned int cmd, void *arg)
  {
  	struct snd_seq_client *client;
  	mm_segment_t fs;
  	int result;
  
  	client = clientptr(clientid);
  	if (client == NULL)
  		return -ENXIO;
  	fs = snd_enter_user();
  	result = snd_seq_do_ioctl(client, cmd, (void __force __user *)arg);
  	snd_leave_user(fs);
  	return result;
  }
  
  EXPORT_SYMBOL(snd_seq_kernel_client_ctl);
  
  /* exported (for OSS emulator) */
  int snd_seq_kernel_client_write_poll(int clientid, struct file *file, poll_table *wait)
  {
  	struct snd_seq_client *client;
  
  	client = clientptr(clientid);
  	if (client == NULL)
  		return -ENXIO;
  
  	if (! snd_seq_write_pool_allocated(client))
  		return 1;
  	if (snd_seq_pool_poll_wait(client->pool, file, wait))
  		return 1;
  	return 0;
  }
  
  EXPORT_SYMBOL(snd_seq_kernel_client_write_poll);
  
  /*---------------------------------------------------------------------------*/
  
  #ifdef CONFIG_PROC_FS
  /*
   *  /proc interface
   */
  static void snd_seq_info_dump_subscribers(struct snd_info_buffer *buffer,
  					  struct snd_seq_port_subs_info *group,
  					  int is_src, char *msg)
  {
  	struct list_head *p;
  	struct snd_seq_subscribers *s;
  	int count = 0;
  
  	down_read(&group->list_mutex);
  	if (list_empty(&group->list_head)) {
  		up_read(&group->list_mutex);
  		return;
  	}
  	snd_iprintf(buffer, msg);
  	list_for_each(p, &group->list_head) {
  		if (is_src)
  			s = list_entry(p, struct snd_seq_subscribers, src_list);
  		else
  			s = list_entry(p, struct snd_seq_subscribers, dest_list);
  		if (count++)
  			snd_iprintf(buffer, ", ");
  		snd_iprintf(buffer, "%d:%d",
  			    is_src ? s->info.dest.client : s->info.sender.client,
  			    is_src ? s->info.dest.port : s->info.sender.port);
  		if (s->info.flags & SNDRV_SEQ_PORT_SUBS_TIMESTAMP)
  			snd_iprintf(buffer, "[%c:%d]", ((s->info.flags & SNDRV_SEQ_PORT_SUBS_TIME_REAL) ? 'r' : 't'), s->info.queue);
  		if (group->exclusive)
  			snd_iprintf(buffer, "[ex]");
  	}
  	up_read(&group->list_mutex);
  	snd_iprintf(buffer, "\n");
  }
  
  #define FLAG_PERM_RD(perm) ((perm) & SNDRV_SEQ_PORT_CAP_READ ? ((perm) & SNDRV_SEQ_PORT_CAP_SUBS_READ ? 'R' : 'r') : '-')
  #define FLAG_PERM_WR(perm) ((perm) & SNDRV_SEQ_PORT_CAP_WRITE ? ((perm) & SNDRV_SEQ_PORT_CAP_SUBS_WRITE ? 'W' : 'w') : '-')
  #define FLAG_PERM_EX(perm) ((perm) & SNDRV_SEQ_PORT_CAP_NO_EXPORT ? '-' : 'e')
  
  #define FLAG_PERM_DUPLEX(perm) ((perm) & SNDRV_SEQ_PORT_CAP_DUPLEX ? 'X' : '-')
  
  static void snd_seq_info_dump_ports(struct snd_info_buffer *buffer,
  				    struct snd_seq_client *client)
  {
  	struct snd_seq_client_port *p;
  
  	mutex_lock(&client->ports_mutex);
  	list_for_each_entry(p, &client->ports_list_head, list) {
  		snd_iprintf(buffer, "  Port %3d : \"%s\" (%c%c%c%c)\n",
  			    p->addr.port, p->name,
  			    FLAG_PERM_RD(p->capability),
  			    FLAG_PERM_WR(p->capability),
  			    FLAG_PERM_EX(p->capability),
  			    FLAG_PERM_DUPLEX(p->capability));
  		snd_seq_info_dump_subscribers(buffer, &p->c_src, 1, "    Connecting To: ");
  		snd_seq_info_dump_subscribers(buffer, &p->c_dest, 0, "    Connected From: ");
  	}
  	mutex_unlock(&client->ports_mutex);
  }
  
  /* exported to seq_info.c */
  void snd_seq_info_clients_read(struct snd_info_entry *entry,
  			       struct snd_info_buffer *buffer)
  {
  	int c;
  	struct snd_seq_client *client;
  
  	snd_iprintf(buffer, "Client info\n");
  	snd_iprintf(buffer, "  cur  clients : %d\n", client_usage.cur);
  	snd_iprintf(buffer, "  peak clients : %d\n", client_usage.peak);
  	snd_iprintf(buffer, "  max  clients : %d\n", SNDRV_SEQ_MAX_CLIENTS);
  	snd_iprintf(buffer, "\n");
  
  	/* list the client table */
  	for (c = 0; c < SNDRV_SEQ_MAX_CLIENTS; c++) {
  		client = snd_seq_client_use_ptr(c);
  		if (client == NULL)
  			continue;
  		if (client->type == NO_CLIENT) {
  			snd_seq_client_unlock(client);
  			continue;
  		}
  
  		snd_iprintf(buffer, "Client %3d : \"%s\" [%s]\n",
  			    c, client->name,
  			    client->type == USER_CLIENT ? "User" : "Kernel");
  		snd_seq_info_dump_ports(buffer, client);
  		if (snd_seq_write_pool_allocated(client)) {
  			snd_iprintf(buffer, "  Output pool :\n");
  			snd_seq_info_pool(buffer, client->pool, "    ");
  		}
  		if (client->type == USER_CLIENT && client->data.user.fifo &&
  		    client->data.user.fifo->pool) {
  			snd_iprintf(buffer, "  Input pool :\n");
  			snd_seq_info_pool(buffer, client->data.user.fifo->pool, "    ");
  		}
  		snd_seq_client_unlock(client);
  	}
  }
  #endif /* CONFIG_PROC_FS */
  
  /*---------------------------------------------------------------------------*/
  
  /*
   *  REGISTRATION PART
   */
  
  static const struct file_operations snd_seq_f_ops =
  {
  	.owner =	THIS_MODULE,
  	.read =		snd_seq_read,
  	.write =	snd_seq_write,
  	.open =		snd_seq_open,
  	.release =	snd_seq_release,
  	.llseek =	no_llseek,
  	.poll =		snd_seq_poll,
  	.unlocked_ioctl =	snd_seq_ioctl,
  	.compat_ioctl =	snd_seq_ioctl_compat,
  };
  
  /*
   * register sequencer device
   */
  int __init snd_sequencer_device_init(void)
  {
  	int err;
  
  	if (mutex_lock_interruptible(&register_mutex))
  		return -ERESTARTSYS;
  
  	if ((err = snd_register_device(SNDRV_DEVICE_TYPE_SEQUENCER, NULL, 0,
  				       &snd_seq_f_ops, NULL, "seq")) < 0) {
  		mutex_unlock(&register_mutex);
  		return err;
  	}
  
  	mutex_unlock(&register_mutex);
  
  	return 0;
  }
  
  /*
   * unregister sequencer device
   */
  void __exit snd_sequencer_device_done(void)
  {
  	snd_unregister_device(SNDRV_DEVICE_TYPE_SEQUENCER, NULL, 0);
  }
  